move masquerade call up, to make sure it is used for start date checks

lms/djangoapps/courseware/module_render.py

@@ -165,14 +165,14 @@ def get_module_for_descriptor(user, request, descriptor, model_data_cache, cours
     Actually implement get_module.  See docstring there for details.
     """
 
-    # Short circuit--if the user shouldn't have access, bail without doing any work
-    if not has_access(user, descriptor, 'load', course_id):
-        return None
-
     # allow course staff to masquerade as student
     if has_access(user, descriptor, 'staff', course_id):
         setup_masquerade(request, True)
 
+    # Short circuit--if the user shouldn't have access, bail without doing any work
+    if not has_access(user, descriptor, 'load', course_id):
+        return None
+
     # Setup system context for module instance
     ajax_url = reverse('modx_dispatch',
                        kwargs=dict(course_id=course_id,